1. Field of the Invention
The present invention relates generally to connectors for coupling cables to terminals, or to one another, etc., and methods for assembling and using the same. More specifically, the invention relates to connectors for coaxial cables and related methods, wherein the connector can provide an environmental sealing role.
2. Description of Related Art
There are many applications in which it is advantageous to connect a coaxial cable to a terminal, another coaxial cable, and the like. Coaxial cable F-connectors, for example, are often used to terminate coaxial cables, such as a drop cable in a cable television system. Such coaxial cables typically include a center or inner conductor surrounded by a dielectric or core, in turn surrounded by an outer conductor or braid, which in turn is surrounded by an outer insulator referred to as a jacket. The F-connector is secured over the prepared end of the jacketed coaxial cable, allowing the end of the coaxial cable to be threadedly connected with a threaded terminal block.
A problem with prior coaxial cable designs, particularly in outdoor applications, has involved unwanted infiltration of moisture at the connector and into the interior of the cable. This can impair performance, for example, by leading to corrosion, affecting the electrical characteristics within the cable, increasing contact resistance, reducing signal strength, causing excessive RF leakage from the connector, etc. Those skilled in the art have made various efforts to form a seal between the connector and the jacket of the coaxial cable to preclude such moisture ingress. Connectors are known in the cable television industry wherein special sealing compounds and/or o-ring seals are included in an effort to form leakproof seals.
Crimp style F-connectors are known, for example, wherein a crimp sleeve is included as part of the connector body. A special radial crimping tool, typically having jaws that form a hexagon, is used to radially crimp the crimp sleeve around the outer jacket of the coaxial cable to secure such a crimp style F-connector over the prepared end of the coaxial cable. Examples of such crimp connectors are disclosed in U.S. Pat. No. 4,400,050 to Hayward, assigned to Gilbert Engineering Co., Inc.; and U.S. Pat. No. 4,990,106 to Szegda. U.S. Pat. No. 4,755,152 to Elliot et al. discloses a crimp connector incorporating a gel or other movable sealing material within a cavity of the connector to form a seal between the jacket of the coaxial cable and the interior of the F-connector.
Still another form of F-connector is known wherein an annular compression sleeve is used to secure the F-connector over the prepared end of the cable. Rather than crimping a crimp sleeve radially toward the jacket of the coaxial cable, these F-connectors employ a plastic annular compression sleeve that is initially attached to the F-connector, but which is detached therefrom prior to installation of the F-connector. The compression sleeve includes an inner bore for allowing the end of the coaxial cable to be passed through such compression sleeve prior to installation of the F-connector. The F-connector itself is then inserted over the prepared end of the coaxial cable. Next, the compression sleeve is compressed axially along the longitudinal axis of the connector into the body of the connector, simultaneously compressing the jacket of the coaxial cable between the compression sleeve and the tubular post of the connector. An example of such a compression sleeve F-connector is shown in U.S. Pat. No. 4,834,675 to Samchisen, which discloses a compression sleeve type F-connector known in the industry as xe2x80x9cSNAP-N-SEAL,xe2x80x9d commercially available from LRC (Thomas and Betts). A number of commercial tool manufacturers provide compression tools for axially compressing the compression sleeve into such connectors. The CablePrep division of Ben Hughes Communication Products Company of Chester, Conn., for example, sells such a hand-operated compression tool under the commercial designation xe2x80x9cTERMINX.xe2x80x9d
The aforementioned xe2x80x9cSNAP-N-SEALxe2x80x9d compression connector requires substantial manipulation by an installer. The installer must detach the annular compression sleeve from the connector, slide the compression sleeve over the end of the coaxial cable, then install the connector, and finally compress the compression sleeve into the body of the connector. During assembly, the compression sleeve can easily become lost because of its typically small size and because it must be detachable from a mounting neck. In addition, such xe2x80x9cSNAP-N-SEALxe2x80x9d connectors are significantly more expensive than conventional crimp style connectors.
Yet another radial compression-type F-connector is disclosed in U.S. Pat. No. 5,470,257 to Szegda. A tubular locking member protrudes axially into the open rear end of the outer collar or sleeve. The tubular locking member is displaceable axially within the outer collar between an open position accommodating insertion of the tubular post into the prepared end of the coaxial cable, and a clamped position fixing the end of the cable within the F-connector. An O-ring is mounted on the rear end of the tubular locking member to seal the connection between the tubular locking member and the outer collar as the tubular locking member is axially compressed. Such connectors have been sold in the past under the designation xe2x80x9cCMPxe2x80x9d by PPC Industries. The O-ring provided on the tubular locking member is exposed and unprotected prior to axial compression of the F-connector.
It is generally known in the coaxial cable field that collars or sleeves within a coaxial cable connector can be compressed inwardly against the outer surface of a coaxial cable to secure a coaxial cable connector thereto. For example, in U.S. Pat. No. 4,575,274 to Hayward and assigned to Gilbert Engineering Company Inc., a connector assembly for a signal transmission system is disclosed wherein a body portion threadably engages a nut portion. The nut portion includes an internal bore in which a ferrule is disposed, the ferrule having an internal bore through which the outer conductor of a coaxial cable is passed. As the nut portion is threaded over the body portion, the ferrule is wedged inwardly to constrict the inner diameter of the ferrule, thereby tightening the ferrule about the outer surface of the cable. In some situations, the connector shown in the Hayward ""274 patent can not be installed quickly, as by a simple crimp or compression tool. Rather, the mating threads of such connector generally must be tightened, for example, using a pair of wrenches.
Known coaxial cable connectors typically require a number of components to secure the cable to the terminal, splice, etc., and attempting to do so in a way that a suitable environmental seal is obtained. The need for these various components results in added relative cost of the components themselves, as well as the costs associated with maintaining parts inventories, assembly time and effort, installation time and effort, etc.
Accordingly, an object of this invention is to provide connectors and related methods wherein a suitable environmental seal is provided to limit or prevent in ingress of moisture into the interior of the cable.
Another object of the invention is to provide connectors and methods that can be made and used economically.
Additional objects and advantages of the invention will be set forth in the description that follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations pointed out in the appended claims.
To achieve foregoing objects, and in accordance with the purposes of the invention as embodied and broadly described in this document, a connector is provided for coupling an end of a coaxial cable to a terminal in accordance with a first aspect of the invention. The first aspect of the invention can be suitable for use with, for example, a coaxial cable comprising an inner conductor, a dielectric surrounding the inner conductor, an outer conductor surrounding the dielectric, and a jacket surrounding the outer conductor.
The connector comprises a coupler comprising a substantially cylindrical portion having a receiving port for engaging the terminal of the coaxial cable. The coupler further comprises an annular collar extending radially inward from the substantially cylindrical portion to provide a collar opening having an opening diameter. The connector further comprises a body member comprising a distal body end, a proximal body end, a proximal body section receivable in the collar opening, and a distal body section. The proximal body section comprises a lip at the proximal body end, the lip having an outer lip diameter greater than the opening diameter. The body member is sufficiently resilient for flexible insertion of the lip through the collar opening. The distal body section extends axially away from the distal coupler end and the proximal body section. The distal body section comprises an inner surface portion. The connector still further comprises a post comprising a distal post end and a proximal post end, the distal post end sized for insertion between the dielectric and the outer conductor. The post further comprises a radially extending post flange movable within the receiving port, and a post shank. The post shank extends from the post flange and forms a post channel sufficient in diameter to receive the inner conductor and the dielectric. The post shank is sufficient in length to extend from the lip to the inner surface portion. The post is movable between a cable-insertion position and a cable-installed position. In the cable-insertion position, the post flange is spaced apart from the lip and the distal post end is spaced sufficiently axially apart from the inner surface portion for inserting coaxial cable into the body member. In the cable-installed position, the post shank is received in the body member to form an annular chamber between the post shank and the inner surface portion. The annular chamber is sufficiently narrow in this cable-installed position to compress the outer conductor and the jacket with the post shank and the inner surface portion for establishing a distal seal. Tightening of the coupler to the terminal compresses the lip between the post flange and the annular collar for establishing a proximal seal.
Preferably, the coupler and post each comprise, and more preferably consist of a metallic, conductive material. Brass is a suitable metallic, conductive material for the coupler and post, although the coupler and post may be the same or different materials. The body member preferably comprises, and more preferably consists of, plastic.
The coupler and terminal preferably each comprises respective threads that, when engaged and tightened, compress the lip between the post flange and the annular collar for establishing the proximal seal. The coupler is preferably a nut.
The body member preferably comprises an annular shoulder integrally connecting the proximal body section and the distal body section to one another, with the collar disposed between the lip and the annular shoulder. In this embodiment, the lip and the annular shoulder are preferably spaced apart by a sufficient distance to permit limited axial movement of the collar of the coupler therebetween before the coupler is engaged with the terminal. The limited axial movement avoids significant engagement of the collar with the lip and permits free-spinning movement of the coupler relative to both the post and the body member until the coupler is tightened onto the terminal.
In another preferred variation of this first aspect of the invention, the lip has a forward chamfer. According to one preferred variation, the lip comprises an elastically deformable material for elastically deforming when the lip is compressed between the post flange and the annular collar. According to another preferred variation, the lip comprises a plastically deformable material for plastically deforming when the lip is compressed between the post flange and the annular collar. Arrangements in which the lip material is partially plastically deformable and/or partially elastically deformable also are possible.
Preferably, the proximal body section and the distal body section are each cylindrical. It is also preferred that the inner surface portion comprise a tapered region tapering radially inward in a direction from the proximal body end towards the distal body end. The post shank is preferably sufficient in length to extend from the lip or proximal body end into the tapered region.
The post shank according to this first aspect of the invention may comprise an outer surface comprising at least one barb, and preferably, a plurality of barbs. These barbs, for example, may be used to grip or trap the outer conductor and the protective outer jacket of the coaxial cable. Preferably, the post is concentric with the coupler and the body member.
According to another preferred embodiment of this first aspect of the invention, the body member further comprises an annular shoulder integrally connecting the proximal body section and the distal body section to one another. The post has an outer surface comprising at least one barb abutting against the distal shoulder end when the post is in the cable-installed position. It is also preferred that the post flange abuts against the proximal end of the body member when the post is in the cable-installed position.
The connector of this first aspect of the invention may be free of any O-rings or sealing compounds, e.g., gels or compounds, for sealing engagement between the coupler, the body member, and the post, although the use of o-rings and/or sealing compounds may be used if desired.
According to a second aspect of the invention, a connector is provided for establishing proximal and distal seals with the terminal and the coaxial cable, respectively. The connector is especially useful with a coaxial cable comprising an inner conductor, a dielectric surrounding the inner conductor, an outer conductor surrounding the dielectric, and a jacket surrounding the outer conductor. According to this second aspect, the connector comprises a coupler comprising an outer portion providing a receiving port for coupling to the terminal. The coupler further comprises an annular collar extending radially inward from the outer portion to provide a collar opening having an opening diameter. The connector further comprises a body member comprising an inner surface portion. The connector further comprises a post having a distal post end and a proximal post end, the distal post end sized for insertion between the dielectric and the outer conductor. The post comprises a radially extending post flange, and a post shank extending from the post flange. The post shank forms a post channel sufficient in diameter to receive the inner conductor and the dielectric. The post shank is sufficient in length to extend from the annular collar to the inner surface portion.
According to this second aspect of the invention, the post is movable between a cable-insertion position and a cable-installed position. In the cable-insertion position, the distal post end is sufficiently spaced apart from the inner surface portion for inserting the coaxial cable into the body member. In the cable-installed position, the post shank is inserted in the body member to form an annular chamber between the post shank and the inner surface portion. The annular chamber is sufficiently narrow to compress the outer conductor and the jacket with the post shank and the inner surface portion for establishing a distal seal.
Preferably, for this second aspect the coupler and post each comprise, and more preferably consist of a metallic, conductive material. Brass or plated brass is a suitable metallic, conductive material for the coupler and post, although the coupler and post may be the same or different materials. The body member preferably comprises, and more preferably consists of, a plastic material.
The body member preferably comprises a proximal body section, a distal body section, and an annular shoulder integrally connecting the proximal body section and the distal body section to one another. In this variation, the proximal body section and the distal body section are each preferably cylindrical.
In another preferred variation of this second aspect of the invention, the body member further comprises a proximal body end and a distal body end, the proximal body end being in closer proximity to the coupler than the distal body end. The inner surface portion comprises a tapered region tapering radially inward in a direction from the proximal body end towards the distal body end. The post shank is preferable sufficient in length to extend from the proximal body end into the tapered region.
The post shank of this second aspect of the invention also may have at least one barb, and preferably a plurality of barbs. Preferably, the post is concentric with the coupler and the body member.
According to another preferred embodiment of this second aspect of the invention, the body member further comprises an annular shoulder integrally connecting the proximal body section and the distal body section to one another. The post has an outer surface comprising at least one barb abutting against the distal shoulder end when the post is in the cable-installed position. It is also preferred that the post flange abuts against the proximal end of the body member when the post is in the cable-installed position.
The connector of this second aspect of the invention optionally may be free of any O-rings or sealing compounds, e.g., gels, for sealing engagement between the coupler, the body member, and the post.
In accordance with a third aspect of the invention, a connector is provided for coupling an end of a coaxial cable to a terminal for establishing a proximal seal between the connector and terminal The connector according to this third aspect of the invention is especially useful with a coaxial cable comprising an inner conductor, a dielectric surrounding the inner conductor, an outer conductor surrounding the dielectric, and a jacket surrounding the outer conductor. The connector according to this third aspect comprises a coupler comprising a substantially cylindrical portion having a receiving port for engaging the terminal, and an annular collar extending radially inward from the substantially cylindrical portion to provide a collar opening having an opening diameter. The connector further comprises a body member and a post. The body member comprises a distal body end, a proximal body end, a proximal body section receivable in the collar opening and comprising a lip at the proximal body end, the lip having an outer lip diameter greater than the opening diameter. The body member is sufficiently resilient for flexible insertion of the lip through the collar opening. The distal body section extends away from the proximal body section. The post comprises a distal post end sized for insertion between the dielectric and the outer conductor, a proximal post end, a radially extending post flange movable within the receiving port, and a post shank. The post shank extends from the post flange. The post shank forms a post channel sufficient in diameter to receive the inner conductor and the dielectric. The post is movable between a cable-insertion position and a cable-installed position. In the cable-insertion position, the post flange is spaced apart from the lip and the coaxial cable is insertable into the body member. In the cable-installed position, the post flange abuts the lip. Tightening the coupler to the terminal compresses the lip between the post flange and the annular collar for establishing a proximal seal.
Preferably, the coupler and post each comprise, and more preferably consist of, a metallic, conductive material. Brass or plated brass is a suitable metallic, conductive material for the coupler and post, although the coupler and post may be the same or different materials. The body member preferably comprises, and more preferably consists of, a plastic.
The coupler preferably rotatably engages the proximal body section to facilitate connection of the coupler to a terminal. The coupler and the terminal each preferably comprise respective threads, which, when engaged with and tightened to one another, compress the lip between the post flange and the annular collar for establishing a proximal seal. The coupler of this variation is preferably a nut.
The body member preferably comprises an annular shoulder integrally connecting the proximal body section and the distal body section to one another, with the collar disposed between the lip and the annular shoulder. In this embodiment, the lip and the annular shoulder are preferably spaced apart by a sufficient distance to permit limited axial movement of the collar of the coupler therebetween before the coupler is tightened to the terminal. The limited axial movement avoids significant engagement with the lip and permits free-spinning movement of the coupler relative to both the post and the body member until the coupler is tightened onto the terminal.
In another preferred variation of this third aspect of the invention, the lip has a forward chamfer. According to one preferred variation, the lip comprises an elastically deformable material for elastically deforming when the lip is compressed between the post flange and the annular collar. According to another preferred variation, the lip comprises a plastically deformable material for plastically deforming when the lip is compressed between the post flange and the annular collar. Partially deformable and/or elastic materials also may be used.
Preferably, the proximal body section and the distal body section are each cylindrical.
The post shank of this third aspect of the invention also may have at least one barb, as described above. Preferably, the post is concentric with the coupler and the body member.
According to another preferred embodiment of this third aspect of the invention, the body member further comprises an annular shoulder integrally connecting the proximal body section and the distal body section to one another. The post has an outer surface comprising at least one barb abutting against the distal shoulder end when the post is in the cable-installed position. It is also preferred that the post flange abuts against the proximal end of the body member when the post is in the cable-installed position.
The connector of this third aspect of the invention also optionally may be free of any O-rings or sealing compounds for sealing engagement between the coupler, the body member, and the post.
In accordance with a fourth aspect of the invention, a method is provided for coupling an end of a coaxial cable to a terminal using a connector, and establishing proximal and distal seals. The coaxial cable comprises an inner conductor, a dielectric surrounding the inner conductor, an outer conductor surrounding the dielectric, and a jacket surrounding the outer conductor. According to this fourth aspect, the method comprises:
(a) providing a coupler comprising a substantially cylindrical portion having a receiving port for engaging the terminal, and an annular collar extending radially inward from the substantially cylindrical portion to provide a collar opening having an opening diameter;
(b) providing a body member comprising a distal body end and a proximal body end, a proximal body section, and a distal body section, the proximal body section being receivable in the collar opening and comprising a lip at the proximal body end, the lip having an outer lip diameter greater than the opening diameter, the body member being sufficiently resilient for flexible insertion of the lip through the collar opening, the distal body section extending away from the proximal body section and comprising an inner surface portion;
(c) inserting the lip through the collar opening while flexing the lip inward to situate the proximal body section in the collar opening;
(d) providing a post comprising a distal post end, a proximal post end, a radially extending post flange movable within the receiving port, and a post shank having a post channel;
(e) passing the coaxial cable into the body member;
(f) moving the post shank through the coupler and into the body member and inserting the post shank between the dielectric and the outer conductor of the coaxial cable to receive the dielectric and the inner conductor in the post channel and to compress the outer conductor and the jacket in an annular chamber between the post shank and the inner surface portion for establishing a distal seal; and
(g) engaging the coupler with the terminal and compressing the lip between the post flange and the annular collar for establishing a proximal seal.
In this fourth aspect, the coupler and the terminal each preferably comprises respective threads that are engaged with and tightened to one another for compressing the lip between the post flange and the annular collar for establishing the proximal seal. The coupler is preferably a nut.
The inner surface portion preferably comprises a tapered region tapering radially inward in a direction from the proximal body end towards the distal body end. The post shank is preferably sufficient in length to extend from the lip or proximal body end into the tapered region.
According to any variation of the fourth embodiment, the body member further comprises an annular shoulder integrally connecting the proximal body section and the distal body section to one another, so that the collar may be situated between the lip and the annular shoulder. The lip preferably has a forward chamfer for facilitating the inserting step (c). The lip and the annular shoulder are preferably spaced apart from one another by a sufficient distance to permit limited axial movement of the collar between the lip and the annular shoulder before the coupler is engaged with the terminal. The limited axial movement avoids significant engagement of the collar with the lip and permits free-spinning movement of the coupler relative to both the post and the body member until the coupler is engaged with the terminal.
The post shank preferably has an outer surface comprising at least one barb, and optionally a plurality of barbs, e.g., for trapping the outer conductor and the jacket of the coaxial cable. In the event that the body member comprises an annular shoulder, one of the barbs may abut against the distal shoulder end to prevent forward movement of the post relative to the distal shoulder end.
The post flange is preferably moved until it abuts against the proximal end of the body member. Compression of the lip between the post flange and the annular collar may comprise elastic deformation and/or plastic deformation, and/or combinations of these.
In accordance with a fifth aspect of the invention, a method is provided for coupling an end of a coaxial cable to a terminal using a connector, and establishing a distal seal. The coaxial cable comprises an inner conductor, a dielectric surrounding the inner conductor, an outer conductor surrounding the dielectric, and a jacket surrounding the outer conductor. According to this fifth aspect, the method comprises:
(a) providing a coupler comprising an outer portion providing a receiving port for coupling to the terminal, and an annular collar extending radially inward from the outer portion to provide a collar opening having an opening diameter;
(b) providing a body member comprising an inner surface portion;
(c) inserting the body member into the annular collar to join the coupler and the body member to one another;
(d) providing a post comprising a distal post end, a proximal post end, a radially extending post flange movable within the receiving port, and a post shank extending from the post flange, the distal post end sized for insertion between the dielectric and the outer conductor, the post shank forming a post channel sufficient in diameter to receive the inner conductor and the dielectric, the post shank being sufficient in length to extend from the annular collar to the inner surface portion,
(e) passing the coaxial cable into the body member; and
(f) moving the post through the coupler and into the body member and inserting the post shank between the dielectric and the outer conductor of the coaxial cable to receive the dielectric and the inner conductor in the post channel and to compress the outer conductor and the jacket in an annular chamber between the post shank and the inner surface portion for establishing a distal seal.
In accordance with this fifth aspect of the invention, the body member preferably further comprises a proximal body end and a distal body end, the proximal body end being in closer proximity to the coupler than the distal body end. The inner surface portion preferably comprises a tapered region tapering radially inward in a direction from the proximal body end towards the distal body end. Preferably, the post shank is sufficient in length to extend from the lip to the tapered region.
As the coaxial cable is passed into the body member, the post flange preferably is maintained axially spaced apart from the annular collar. The post shank preferably has an outer surface comprising at least one barb or a plurality of barbs. As the post shaft is moved per step (f), the barb traps the outer conductor and the jacket of the coaxial cable. In the event that the body member comprises an annular shoulder integrally connecting proximal and distal body sections of the body member, the barb against the distal shoulder end to prevent forward movement of the post relative to the distal shoulder end.
The moving step (f) may be conducted abut the post flange against the proximal end of the body member.
In accordance with a sixth aspect of the invention, a method is provided for coupling an end of a coaxial cable to a terminal using a connector, and for establishing a proximal seal. The coaxial cable comprises an inner conductor, a dielectric surrounding the inner conductor, an outer conductor surrounding the dielectric, and a jacket surrounding the outer conductor. According to this sixth aspect, the method comprises:
(a) providing a coupler comprising a substantially cylindrical portion having a receiving port for engaging the terminal, and an annular collar extending radially inward from the substantially cylindrical portion to provide a collar opening having an opening diameter;
(b) providing a body member comprising a proximal body end, a distal body end, a proximal body section comprising a lip having an outer lip diameter greater than the opening diameter, and a distal body section extending axially away from the proximal body section;
(c) inserting the lip through the collar opening while flexing the lip inward to situate the proximal body section in the collar opening;
(d) providing a post comprising a distal post end, a proximal post end, a radially extending post flange movable within the receiving port, and a post shank having a post channel;
(e) passing the coaxial cable into the body member;
(f) moving the post shank through the coupler and into the body member and inserting the post shank between the dielectric and the outer conductor of the coaxial cable to receive the dielectric and the inner conductor in the post channel and to receive the outer conductor and the jacket in an annular chamber between the post shank and the inner surface portion; and
(g) engaging the coupler with the terminal and compressing the lip between the post flange and the annular collar for establishing a proximal seal.
In accordance with the sixth aspect, preferably each of the coupler and the terminal comprises respective threads, and the respective threads are tightened to compress the lip between the post flange and the annular collar for establishing the proximal seal. The coupler preferably is a nut.
In a preferred modification to the sixth aspect, the body member further comprises an annular shoulder integrally connecting the proximal body section and the distal body section to one another, and the (c) inserting comprises situating the collar between the lip and the annular shoulder. The lip may optionally have a forward chamfer for facilitating insertion of the lip through the annular collar. The lip and the annular shoulder may be spaced apart by a sufficient distance to permit limited axial movement of the collar between the lip and the annular shoulder before the coupler is tightened to the terminal. The limited axial movement avoids significant engagement of the collar with the lip and permits free-spinning movement of the coupler relative to both the post and the body member until the coupler is engaged with the terminal.
The post shank of this sixth aspect preferably has an outer surface comprising at least one barb, wherein the (f) moving comprises trapping the outer conductor and the jacket of the coaxial cable with the barb. In the event that the body member further comprises an annular shoulder integrally connecting the proximal body section and the distal body section to one another, the (f) moving step may comprise abutting the barb against the distal shoulder end to prevent forward movement of the post relative to the distal shoulder end.
According to one variation of the sixth aspect, compressing of the lip between the post flange and the annular collar comprises elastically deforming the lip. According to another variation of the sixth aspect, compressing of the lip between the post flange and the annular collar comprises plastically deforming the lip. Combinations of these also are possible.